Purpose
This study was designed to examine the feasibility of combining lymphoscintigraphy and intraoperative sentinel node identification in patients with head and neck melanoma by using a hybrid ...protein colloid that is both radioactive and fluorescent.
Methods
Eleven patients scheduled for sentinel node biopsy in the head and neck region were studied. Approximately 5 h before surgery, the hybrid nanocolloid labeled with indocyanine green (ICG) and technetium-99m (
99m
Tc) was injected intradermally in four deposits around the scar of the primary melanoma excision. Subsequent lymphoscintigraphy and single photon emission computed tomography with computed tomography (SPECT/CT) were performed to identify the sentinel nodes preoperatively. In the operating room, patent blue dye was injected in 7 of the 11 patients. Intraoperatively, sentinel nodes were acoustically localized with a gamma ray detection probe and visualized by using patent blue dye and/or fluorescence-based tracing with a dedicated near-infrared light camera. A portable gamma camera was used before and after sentinel node excision to confirm excision of all sentinel nodes.
Results
A total of 27 sentinel nodes were preoperatively identified on the lymphoscintigraphy and SPECT/CT images. All sentinel nodes could be localized intraoperatively. In the seven patients in whom blue dye was used, 43% of the sentinel nodes stained blue, whereas all were fluorescent. The portable gamma camera identified additional sentinel nodes in two patients. Ex vivo, all radioactive lymph nodes were fluorescent and vice versa, indicating the stability of the hybrid tracer.
Conclusions
ICG–
99m
Tc-nanocolloid allows for preoperative sentinel node visualization and concomitant intraoperative radio- and fluorescence guidance to the same sentinel nodes in head and neck melanoma patients.
The reliability of sentinel node biopsy is dependent on the accurate visualization and identification of the sentinel node(s). It has been suggested that extensive metastatic involvement of a ...sentinel node can lead to blocked inflow and rerouting of lymph fluid to a "neo-sentinel node" that may not yet contain tumor cells, causing a false-negative result. However, there is little evidence to support this hypothesis. Recently introduced hybrid SPECT/CT scanners provide both tomographic lymphoscintigraphy and anatomic detail. Such a scanner enabled the present study of the concept of tumor blockage and rerouting of lymphatic drainage in patients with palpable groin metastases.
Seventeen patients with unilateral palpable and cytologically proven metastases in the groin underwent bilateral conventional lymphoscintigraphy and SPECT/CT before sentinel node biopsy of the contralateral groin. The pattern of lymphatic drainage in the 17 palpable groin metastases was evaluated for signs of tumor blockage or rerouting.
On the CT images, the palpable node metastases could be identified in all 17 groins. Four of the 17 palpable node metastases (24%) showed uptake of radioactivity on the SPECT/CT images. In 10 groins, rerouting of lymphatic drainage to a neo-sentinel node was seen; one neo-sentinel node was located in the contralateral groin. A complete absence of lymphatic drainage was seen in the remaining 3 groins.
The concept of tumor blockage and rerouting was visualized in 76% of the groins with palpable metastases. Precise physical examination and preoperative ultrasound with fine-needle aspiration cytology may identify nodes with considerable tumor invasion at an earlier stage and thereby reduce the incidence of false-negative results.
Purpose
The aim of this study was to assess the accuracy of
18
F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT to visualize lymph node metastases before the start of neoadjuvant ...chemotherapy and to determine how often the visualization is sufficiently prominent to allow monitoring of the axillary response.
Methods
Thirty-eight patients with invasive breast cancer of >3 cm and/or lymph node metastasis underwent FDG PET/CT before neoadjuvant chemotherapy. The results of the FDG PET/CT were compared with those from ultrasonography with fine-needle aspiration (FNA) cytology or sentinel node biopsy. Patients suitable for response monitoring of the axilla were defined as having either a maximum standardized uptake value (SUV
max
) ≥ 2.5 or a tumour to background ratio ≥5 in the most intense lymph node.
Results
The sensitivity and specificity of FDG PET/CT in detecting axillary involvement were 97 and 100%, respectively. No difference existed between the SUV
max
of the primary tumour and that from the related most intense lymph node metastasis. Moreover, the mean tumour to background ratio was 90% higher in the lymph nodes compared to the primary tumour (
p
= 0.006). Ninety-three per cent of the patients had sufficient uptake in the lymph nodes to qualify for subsequent response monitoring of the axilla. A considerable distinction in metabolic activity was observed between the different subtypes of breast cancer. The mean SUV
max
in lymph node metastases of oestrogen receptor (ER)-positive, triple-negative and human epidermal growth factor receptor 2 (HER2)-positive tumours was 6.6, 11.6 and 6.6, respectively.
Conclusion
The high accuracy in visualizing lymph node metastases and the sufficiently high SUV
max
and tumour to background ratio at baseline suggest that it is feasible to monitor the axillary response with FDG PET/CT, especially in triple-negative tumours.
The recently introduced SPECT/CT integrates the physiologic data of SPECT with the anatomic data of CT into a single image. The purpose of this pilot study was to explore the additional value of ...SPECT/CT in breast cancer patients and melanoma patients with inconclusive planar image findings.
Thirty-one patients had planar lymphoscintigrams showing unexpected lymphatic drainage, 6 had lymphoscintigrams that were difficult to interpret, and 3 showed no drainage on planar imaging. SPECT/CT was performed immediately after delayed planar imaging.
In 4 patients, SPECT/CT showed 6 additional sentinel nodes, of which 2 were tumor-positive and led to upstaging and tailored management in 5% of patients. SPECT/CT depicted sentinel nodes in 3 patients whose delayed planar imaging had shown no drainage.
SPECT/CT was of additional value in finding the exact anatomic location of sentinel nodes in patients with inconclusive planar image findings. SPECT/CT also detected sentinel nodes in addition to those found on planar images, and SPECT/CT detected sentinel nodes in patients whose planar images had shown none.
Laparoscopic evaluation of sentinel nodes is useful for staging prostate cancer, but preoperative localization of deep abdominal sentinel nodes with planar lymphoscintigraphy is difficult. We ...evaluated the value of SPECT/CT for detecting and localizing sentinel nodes in prostate cancer.
(99m)Tc-nanocolloid was injected peri- and intratumorally, guided by transrectal ultrasonography, in 46 patients with prostate cancer of intermediate prognosis. Patients underwent planar imaging after 15 min and 2 h, SPECT/CT after 2 h, and laparoscopic sentinel node lymphadenectomy on the same day. SPECT was fused with CT and analyzed using 2-dimensional orthogonal slicing and 3-dimensional volume rendering. We evaluated the number of extra sentinel nodes found by SPECT/CT, the number of sentinel nodes found by SPECT/CT outside the area of the extended pelvic lymphadenectomy, and the anatomic information provided by SPECT/CT. Furthermore, we classified the value of the additional SPECT/CT images into 3 categories (no advantage, presumable advantage, and definite advantage) according to the extra anatomic information given and whether additional sentinel nodes were found by SPECT/CT.
The patients had a mean age of 64 y (range, 53-74 y) and received a mean injected dose of 218 MBq (range, 147-286 MBq). The sentinel node visualization rate was 91% (42 patients) for planar imaging and 98% (45 patients) for SPECT/CT. In 29 of the 46 patients (63%), SPECT/CT revealed additional sentinel nodes (especially lymph nodes near the injection area) not seen on planar imaging. In 7 patients, those additional sentinel nodes were positive for metastasis (being the exclusive metastatic sentinel node in 4 patients). Overall, 15 patients (33%) had positive sentinel nodes. Sentinel nodes outside the area of extended pelvic lymphadenectomy were found in 16 patients (35%), whereas in 56% of these patients those nodes were not seen on planar imaging. Performing SPECT/CT had no advantage in 13% of the patients, a presumable advantage in 24%, and a definite advantage in 63%. Urologic surgeons used the SPECT/CT images to guide their trocar insertion sites and sentinel node finding with the probe.
More sentinel nodes can be detected with SPECT/CT than with planar imaging alone. In comparison with planar imaging, SPECT/CT especially reveals extra sentinel nodes near the prostate and outside the area of the extended pelvic lymphadenectomy. Furthermore, the modality provides useful additional information about the anatomic location of sentinel nodes within and outside the pelvic area, leading to improved intraoperative sentinel node identification.
Purpose
To determine the lymphatic drainage pattern using SPECT/CT in clinically node-negative (cN0) patients with vulvar cancer, and to evaluate the possible implications for the extent of inguinal ...lymph node dissection.
Methods
A total of 83 patients with vulvar cancer scheduled for sentinel node (SN) biopsy were injected peritumorally with radioactive nanocolloid particles followed by lymphoscintigraphy and SPECT/CT for anatomical localization. The SN and higher-echelon nodes on SPECT/CT were located in different zones in the groin and pelvic region. The groin was divided into five zones according to Daseler et al.: four zones obtained by drawing two perpendicular lines over the saphenofemoral junction and one zone directly overlying this junction. The nodes in the pelvic region were classified into three zones: external iliac/obturator, the common iliac and the paraaortic zones.
Results
A total of 217 SNs and 202 higher-echelon nodes were localized on SPECT/CT. All SNs were located in the five zones according to Daseler et al.: 149 (69 %) in the medial superior region, 31 (14 %) in the medial inferior region, 22 (10 %) in the central region, 14 (6.5 %) in the lateral superior region and only 1 (0.5 %) in the lateral inferior region. The higher-echelon nodes were located both in the groin (15 %) and in the pelvic region (85 %).
Conclusion
In patients with cN0 vulvar cancer, lymphatic drainage occurs predominantly to the medial regions of the groin. Drainage to the lateral inferior region of the groin is only incidental and in SN-positive patients this zone might be spared in subsequent extended lymph node dissection. This may lead to a decrease in the morbidity associated with this procedure. SPECT/CT is able to personalize lymphatic mapping, providing detailed information about the number and anatomical location of SNs for adequate surgical planning in the groin.
Background
In recent years repeat sentinel node (SN) biopsy has been proven to be feasible in local breast cancer recurrence (LBCR). However, in these patients SNs outside the ipsilateral axilla are ...frequently observed. This study evaluates the contribution of SPECT/CT for SN localization and surgical adjustment in LBCR patients.
Methods
SN biopsy was performed in 122 LBCR patients (median age 60.5 years, range 24–87), enrolled from August 2006 to July 2015. Median disease-free time lapse was 109.5 months (range 9–365). Axillary lymph node dissection (ALND) had previously been performed in 55 patients, SN biopsy in 44, both techniques in 13 and fine-needle aspiration in 10. Primary breast cancer treatment included radiotherapy in 104 patients (85.3 %) and chemotherapy in 40 (32.8 %). Preoperative lymphatic mapping, using planar scintigraphy (PS) and SPECT/CT included report of SN location according to lymph node territory. In case of a territorial PS-SPECT/CT mismatch, surgery was adjusted according to SPECT/CT findings.
Results
SPECT/CT SN visualization rate was higher than PS (53.3 % vs. 43.4 %, p n.s.) with, in total, 19 additional SN (118 vs. 99, p n.s.). PS-SPECT/CT territory mismatch, found in 60 % (39/65) of patients with SN visualization, led to surgical adjustment in 21.3 % (26/122) of patients. The SN procedure was finally performed in 104 patients resulting in a 65.7 % surgical retrieval rate with a total of 132 removed SNs (1.86/patient). SN metastases were found in 17/71 patients (23.9 %), in 16 of them (94 %) in ipsilateral basins outside the axilla or in the contralateral axilla.
Conclusion
Using SPECT/CT there is a trend to visualize more SNs in LBCR, providing at the same time important anatomical information to adjust intraoperative SN procedures. The addition of SPECT/CT to the standard imaging protocol may lead to better staging mainly in patients presenting drainage outside the ipsilateral axilla.
Advances in radioguided surgery in oncology Valdés Olmos, Renato A; Vidal-Sicart, Sergi; Manca, Gianpiero ...
The quarterly journal of nuclear medicine and molecular imaging,
09/2017, Volume:
61, Issue:
3
Journal Article
Peer reviewed
The sentinel lymph node (SLN) biopsy is probably the most well-known radioguided technique in surgical oncology. Today SLN biopsy reduces the morbidity associated with lymphadenectomy and increases ...the identification rate of occult lymphatic metastases by offering the pathologist the lymph nodes with the highest probability of containing metastatic cells. These advantages may result in a change in clinical management both in melanoma and breast cancer patients. The SLN evaluation by pathology currently implies tumor burden stratification for further prognostic information. The concept of SLN biopsy includes pre-surgical lymphoscintigraphy as a "roadmap" to guide the surgeon toward the SLNs and to localize unpredictable lymphatic drainage patterns. In addition to planar images, SPECT/CT improves SLN detection, especially in sites closer to the injection site, providing anatomic landmarks which are helpful in localizing SLNs in difficult to interpret studies. The use of intraoperative imaging devices allows a better surgical approach and SLN localization. Several studies report the value of such devices for excision of additional sentinel nodes and for monitoring the whole procedure. The combination of preoperative imaging and radioguided localization constitutes the basis for a whole spectrum of basic and advanced nuclear medicine procedures, which recently have been encompassed under the term "guided intraoperative scintigraphic tumor targeting" (GOSTT). Excepting SLN biopsy, GOSTT includes procedures based on the detection of target lesions with visible uptake of tumor-seeking radiotracers on SPECT/CT or PET/CT enabling their subsequent radioguided excisional biopsy for diagnostic of therapeutic purposes. The incorporation of new PET-tracers into nuclear medicine has reinforced this field delineating new strategies for radioguided excision. In cases with insufficient lesion uptake after systemic radiotracer administration, intralesional injection of a tracer without migration may enable subsequent excision of the targeted tissue. This approach has been helpful in non-palpable breast cancer and in solitary pulmonary nodules. The introduction of allied technologies like fluorescence constitutes a recent advance aimed to refine the search for SLNs and tracer-avid lesions in the operation theatre in combination with radioguidance.
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